1. Field of the Invention
The present invention relates to a transparent glass substrate comprising at least one face which is provided with a plurality of geometric features in relief relative to a general plane of the face. The invention also relates to a module for collecting energy originating from radiation incident on the module, in particular solar radiation, comprising such a substrate as the front substrate of the module. Moreover, the invention relates to a process for manufacturing such a transparent glass substrate.
Within the meaning of the invention, a module for collecting energy originating from radiation may be, in particular, a photovoltaic solar module, capable of converting the energy originating from solar radiation into electrical energy, or a thermal solar module, capable of converting energy originating from solar radiation into thermal energy collected in a heat transfer fluid.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Conventionally, a module for collecting energy originating from solar radiation comprises a front substrate, or a substrate having a glass function, which provides a mechanical protection for the energy conversion elements, namely the photovoltaic cell or cells in the case of a photovoltaic module, while allowing a good transmission of the solar radiation to these energy conversion elements. The front substrate may especially be constituted of a transparent glass, preferably clear or extra-clear glass, having a very low content of iron oxides, such as the glass “DIAMANT” or the glass “ALBARINO” sold by Saint-Gobain Glass.
One strategy for increasing the energy conversion efficiency of an energy-collecting module consists of improving the transmission properties of the front substrate, by limiting the reflection of the radiation incident on the module at the interface between the air and the front substrate. For this purpose, it is known to texture at least the front face of the substrate, intended to be positioned on the side on which radiation is incident on the module, by providing it with a plurality of geometric features in relief that are concave or convex relative to a general plane of this face. Within the meaning of the invention, the general plane of a textured face is the plane containing the points of this face which do not form part of the features in relief or, in the case of contiguous features, the points at the junctions between the features in relief. With a view to obtaining an effective improvement of its transmission properties, the substrate is advantageously provided with a sloping texturing, in particular a texturing which has a high aspect ratio, defined as being the ratio of the thickness of the features in relief constituting the texturing to the width of these features, especially an aspect ratio of greater than 0.1. The features in relief may be pyramids or cones, or else features that have a favored longitudinal direction, such as grooves or ribs. However, the efficiencies of modules that integrate such textured front substrates remain limited.
It is these drawbacks that the invention intends more particularly to solve by proposing a transparent glass substrate which, when it is integrated as a front substrate in a module for collecting energy originating from radiation, in particular solar radiation, has optimized transmission properties of the radiation incident on the substrate to the energy conversion elements of the module, thus enabling an improvement of the efficiency of this module compared to modules from the prior art, while preferably having a manufacturing process that is simple and is capable of being easily industrialized.